The research program of this laboratory deals with the isolation, properties and biological activities of proteins associated with DNA in the chromosomes of higher organisms. Particular emphasis is placed on reactions which modify the structure of nuclear proteins after synthesis is completed - such as acetylation, methylation, and phosphorylation of lysine and serine residues in the polypeptide chains. The chemical and enzymatic basis of these reactions, and their results in terms of DNA-protein interactions are a major topic of investigation. Related projects deal the events occurring in the cell nucleus at times of gene activation by mitogenic agents, and during early stages of chemical carcinogenesis - with particular attention to changes in nuclear phosphoprotein composition and metabolism.